Some active workers also face the prospect of shopping for their own coverage, to a certain extent using money supplied by their employer, as federal and state officials grant employers more freedom. Missouri passed a law earlier this year making it easier for small employers to give workers money towards individual health policies. The Internal Revenue Service has also endorsed the idea of employers reimbursing workers for individual health premiums, lifting a regulatory cloud.

Such trends elucidate why health care has become a big issue in the presidential campaign. President Bush and the leading Republican presidential candidates in general embrace the idea of individuals shouldering more responsibility and risk for their health care, although with help from employers or the government where needed. Mr. Bush sees individual health accounts as one pillar of an "ownership society."

On the other hand, such notions have proved a tough sell in Congress. Mr. Bush's tax proposals to encourage a shift away from the employer-based market never got off the ground. Currently, people do not get a tax break when they use their own money to purchase insurance, and the federal tax system encourages employer-based coverage.

Shifting people to the individual market is challenging for other reasons, at least under the current set-up. It is complicated for people to understand what they are buying, and those with existing illnesses have trouble finding any coverage.

The top Democratic presidential candidates have built their health-care plans around bolstering employer-based insurance, but they also envisage further government action to help the uninsured or underinsured. For instance, more than a few would impose some kind of requirement on insurers to cover all comers.

In an interview, Sen. Hillary Rodham Clinton said people are not ready to cross employers out of the equation. "We looked at every permutation of how you get to universal health care," said the Democratic presidential candidate. "There's great attachment to the employer-based system, even though it is eroding."